i have a 86 735i the battery went dead after a long weekend away with my roommate (due to me leaving my radar detector on) I took the battery out charged it and put it back in ever sence then the mode selector switch just springs back to economy when i try to change it and i only have reverse and 3rd gear. i read the owners man and it says it due to an electrical malfunction but i dont even know where to begin to look for what is wrong/how to fix it.. any help i can get would be greatly appreciated

hi again well i broke either the diff or cv joints so im working on getting a parts 89 735i that i will part out (so make offers on parts) but before i broke it i found that putting a jumper wire across the wires in the bottom connector for the S-E-123 switch made it shift correctly. so now im thinking (due to staring at a wiring diagram for hours & trying a diff S-E-123 switch, and trans computer) that it must be the P-R-N-D-3-2-1 switch any ideas and/or parts requests